The long-range goal for this project is to determine how hepatotoxic and carcinogenic agents modify the carbohydrate metabolism of rat liver. Studies to date have shown that beta-adrenergic control of hepatic phosphorylase activation becomes equivalent to that of the alpha-adrenergic control in young rats, in rats after a 67% hepatectomy, and in rats fed 2-acetylaminofluorene for 2-4 weeks. The next portion of the project will involve attempting to estimate the numbers and affinities of the alpha-adrenergic and beta-adrenergic receptors in hepatic plasma membranes obtained from rats treated as given above. Studies will be done also to assess the gluconeogenic capacity and the glycogen synthetic ability of livers of rats fed 2-acetylaminofluorene for 2-4 weeks.